1. Technical Field
The present invention relates generally to robotic dispensing systems and more particularly to a gear pump dispenser integrated with a robotic assembly for robotic dispensing of a viscous material.
2. Discussion
The use of robots to implement numerous manufacturing processes has increased dramatically in the last decade. Robots now perform various manufacturing operations such as dispensing, deburring, grinding, polishing, painting, finish coating, cutting, welding, and others. A well-adjusted robot enables enhanced control and repeatability of the manufacturing process.
In one robotically implemented manufacturing process, structural components are secured together using a viscous adhesive applied by an automated robotic system. Materials such as PVC based sealants and adhesives, heat cure epoxies, two-component epoxies and others are typical of viscous materials commonly applied through use of robotic systems. Commonly, a gear pump is utilized to pump the viscous material to a dispense valve from which it is emitted.
Robotic dispensing systems generally dispense a bead of the viscous material along a perimeter or other desired pathway of the structural member. Often, the adhesive bead is dispensed such that it maintains a desired shape over the entire pathway along the application area. To accomplish this, the robotic system is configured to rotate the dispensing valve as the dispensing proceeds so that the orientation of the valve with respect to the structural member is controlled. Therefore, the dispensing orifice of the valve, which is usually shaped to emit the material in its predetermined form, dispenses the shaped bead of material in a proper orientation.
In other applications, however, the desired shape of the adhesive bead is symmetrical, i.e., cylindrical or round. Therefore, the orientation of the dispensing valve with respect to the structural member is largely unconstrained. In other words, there is no requirement for the dispensing valve to be rotated as it tracks along the application surface.
Conventional robotic dispensing systems use one dispensing configuration for emitting either a symmetrical bead or a shaped bead. In this configuration, the dispense valve is mounted to the end of a positionable arm along an axis of rotation. The gear pump is often mounted on the shoulder of a robot and utilizes a separate motor, controller, and reduction gear to operate. A whip hose or other conduit interconnects the shoulder mounted gear pump and the dispense valve.
Until recently, this axis of rotation, commonly known in the art as the sixth axis, was limited to rotating only 360.degree. in a first direction or 360.degree. in a second direction. However, advancements in robotic systems have increased the rotation of the sixth axis. The sixth axis is now able to rotate in a first or second direction perpetually.
Therefore, it is an object of the present invention to provide a dispensing system utilizing the perpetual rotation of the sixth axis to drive a gear pump such that the complexity and cost of prior systems is reduced. Additionally, it is an object of the present invention to provide a dispensing system eliminating the need for a separate motor and controller for operating the gear pump. Furthermore, it is an object of the present invention to provide a dispensing system eliminating the need for a whip hose between the gear pump and dispense valve.